I've owned both manual and tip versions of B6 S4's and the tip get's my vote.
For spirited driving the manual get's my vote, though found the bite point of clutch to be quite high, which made round town stop start driving to be a chore. Typically used to use 2nd for pulling off in such scenarios as 1st gear was quite "digital" with an on / off effect to all but the lightest of right foot tickling and the 1st to 2nd change was a tough one to make silky smooth - it can be done, but not when driving lazily. I also used to short shift a lot 2nd to 4th ... using the torque, so again, for a wide amount of regular use, I was not using the full potential of the box.
The tip in standard mode is "relaxed"... you'd not know you're in a sports saloon without really encouraging kick down or gear holding under hard acceleration - and even then, it tends to hold bakc before a change, to make sure you really want to cane it - maybe thinking instead I just sneezed and had a throttle flutter?
It changes up early in full auto, just as the engine starts to come alive over 2.5K, so it's a quiet and sombre program, perfectly suited to a wide ragne of driving styles and driving conditions - it does really what it needs to for a car of this nature that is sold the world over to such a wide user base.
However in sport or any of the the other modes available, it truly is like a different car. Again, it's not quite as flexible as a manual, but in terms of required control off the track, it's more than capable for most situations.
The tip has never felt quite as fast to me as the manual, but that may be driver engagement playing a part whereas in sport you're just concentrating on the feeling of ****** all, to ****** me, to ****** this
If you can, try both. For an everyday driver, I went for a tip this time around and am pleased with my choice.
Now a DSG variant ... that might be the next temptation I find hard to resist.